Accurate structural parameters and binding energy of the state of diazomethane through coupled-cluster calculations

Through coupled-cluster CCSD(T) calculations combined with extended correlation consistent basis sets, we have determined accurate structural parameters of the ground X 1 ̃ A 1 state of the H2CN2 molecule. In particular, the hitherto doubtful dissociation energy H2C–N2 has been pinpointed to D 0 0 = 27.3 kcal / mol with respect to CH 2 ( X ̃ 3 B 1 ) + N 2 ( X 1 Σ g + ) .